Research activities of the “Biology of the egg and physiology of the hen” team

Team leader: Sophie Réhault-Godbert

General objectives:

- The first objective of the team is to acquire fundamental knowledge on the physiology of the laying hen and the biological functions of the egg. 

- The second objective is to improve the sustainability of laying hen rearing and egg production by 

1) identifying markers of egg quality (eggs for human consumption and hatching eggs), 

2) improving laying hen production practices, and 

3) optimizing egg storage conditions and incubation practices. 

Topics:

- Calcium homeostasis (bone health in laying hens, shell quality and embryo skeletal quality)

Shell (calcium carbonate) synthesis takes place in the hen's uterus and depends on the bioavailability of calcium, part of which is stored in the hen's skeleton. Our goal is to understand the physiological mechanisms involved in the transfer of minerals from the gut to the hen's bone, from the bone to the eggshell, and from the eggshell to the embryonic skeleton. At the same time, we are exploring different strategies to maintain the bone health of the hen while ensuring the quality of the eggshell and skeleton of the future chick.

- Egg formation

To improve our understanding of the physiology of egg formation and the characteristics of the different egg compartments, we use complementary approaches, in particular protein biochemistry, molecular biology and imaging techniques. Some projects also include comparative biology approaches between eggs from different breeds of hens and other bird species.

-Biological functions of egg

A better structural characterisation of the extra-embryonic structures and molecular components of the egg, combined with the study of their activities and evolution during embryonic development, will allow us to define their respective physiological roles during embryonic development.

The biochemical and functional characterisation of purified (or recombinant) proteins and the elucidation of their three-dimensional structure contribute to a better understanding of the structure-activity relationships of egg proteins and the impact of certain natural protein polymorphism on egg quality.

Some of these activities (in particular the antimicrobial activity of proteins) can be of interest in human health, as alternatives to conventional antibiotics, or in the food industry (preservatives). Similarly, the identification of proteins involved in eggshell mineralisation may have applications in the production of organic additives for the materials industry.

- Quality of table eggs (unfertilised)

The sanitary quality of eggs depends essentially on the integrity of the eggshell and the internal structures of the egg (in particular the white and vitelline membranes), which limit the penetration and development of pathogens responsible for food-borne contaminations. The integrity of the various structures of the egg is assessed using indicators of freshness and/or quality that reflect the physical and physicochemical characteristics of egg structures.

We are particularly interested in the effects of various hen-related factors (genetics, age, nutrition, rearing system, etc.) and egg storage conditions (duration, temperature, and atmosphere) on these indicators and on the biochemical composition of the egg compartments. We are also studying contrasting conditions (optimal versus degraded) to identify quality markers for table eggs (molecular markers and gene polymorphisms), some of which could potentially be used in selection schemes to improve egg quality.

_- Characterisation and quality of fertilised eggs

In poultry farming, fertilised eggs are used to produce future broilers (meat) and laying hens (eggs for consumption). To improve egg viability and optimise embryo development, we are exploring different storage and incubation conditions for fertilised eggs.

In addition, by comparing the molecular and structural characteristics of eggs containing a male embryo with those of eggs containing a female embryo, we are trying to identify embryo sex markers that could eventually be used to develop of early ovo-sexing tools.

On-going projects:

- BPI France 2030. Nouvelle solution de sexage in ovo. 2024-2026. 

- UMT BECOME - Bien-être, Éleveurs, COnsommateurs et MarchEs. 2023-2028.

- Contrat de Recherche partenariale Institut Carnot F2E HEEBS « HyD Effect on Egg and Bone Status ». 2022-2025. 

Past projects:

- H2020 PPILOW, Poultry and PIg Low-input and Organic production systems’ Welfare 2019-2024.
- ANR EQLIPSE, Enhancing the Quality and the Level of Internal Protections of Shell Eggs. 2019-2024.
- CASDAR Chick’tip. 2018-202.- Contrat de Recherche partenariale Institut Carnot F2E “Bone and EggShell Quality ». 2018-2022.
- Contrat de Recherche Partenariale Institut Carnot F2E « D-shell ». 2019. Coordinateur.
- Contrats de Recherche Partenariale Institut Carnot F2E « D-shell2 et D-Shell2 Proteomics ». 2021-2022.
- Contrat de Recherche d’Intérêt Régional Centre Val de Loire « Volailles ». 2018-2022. Valorisation de l’Origine, Liens entre Acteurs, Identités LocaLes, Évolutions du Secteur avicole.
- Projet de Recherche AGENAVI « Polcacao ». 2019-2021. POLymorphismes CAndidats de la CAlcification de la coquille de l’Œuf de poule.
- Contrat Studium Professorship. Maxwell Hincke (Univ. Ottawa). 2018-2022. Innate immunity at biomineralized barriers

- SAPhyR-11, Structure-Activity and Phylogenetic Relationships of avian beta-defensin 11. 2017-2020. Région Centre Val de Loire.

- UMT-BIRD (aviculture, système et territoire). 2017-2021.

Major publications :

Maeva Halgrain, Maris Schneider, Shumeng Jia, Agnès Narcy, Eric Gambier, et al.. A 3D micro-computed tomography study comparing embryonic skeletal development in layer versus broiler strains of the domestic chicken. Poultry Science, 2024, 103 (12), pp.104308. ⟨10.1016/j.psj.2024.104308⟩. ⟨hal-04711691⟩

A.B. Rodríguez-Navarro, N. Domínguez-Gasca, D. Athanasiadou, N. Le Roy, A. González-Segura, et al.. Guinea fowl eggshell structural analysis at different scales reveals how organic matrix induces microstructural shifts that enhance its mechanical properties. Acta Biomaterialia, 2024, 178, pp.244-256. ⟨10.1016/j.actbio.2024.03.001⟩. ⟨hal-04500196⟩

Thierry Moreau, Emilie Recoules, Marion de Pauw, Valérie Labas, Sophie Réhault-Godbert. Evidence that the Bowman-Birk Inhibitor from Pisum sativum affects intestinal proteolytic activities in chickens. Poultry Science, 2024, 103 (1), pp.103182. ⟨10.1016/j.psj.2023.103182⟩. ⟨hal-04270641⟩

Maeva Halgrain, Nelly Bernardet, Christelle Hennequet-Antier, Sophie Réhault-Godbert. Sex-specific transcriptome of the chicken chorioallantoic membrane. Genomics, 2024, 116 (1), pp.110754. ⟨10.1016/j.ygeno.2023.110754⟩. ⟨hal-04356368⟩

F Hervo, M.-P Létourneau-Montminy, N Même, Bertrand Méda, Michel Jacques M.J. Duclos, et al.. Effect of phytase and limestone particle size on mineral digestibility, performance, eggshell quality, and bone mineralization in laying hens. Poultry Science, 2023, 102 (5), pp.102613. ⟨10.1016/j.psj.2023.102613⟩. ⟨hal-04151063⟩

Hans Adriaensen, Vanille Parasote, Ines Castilla, Nelly Bernardet, Maëva Halgrain, et al.. How Egg Storage Duration Prior to Incubation Impairs Egg Quality and Chicken Embryonic Development: Contribution of Imaging Technologies. Frontiers in Physiology, 2022, 13, ⟨10.3389/fphys.2022.902154⟩. ⟨hal-03683203⟩

Nicolas Guyot, Céline Landon, Philippe Monget. The Two Domains of the Avian Double-β-Defensin AvBD11 Have Different Ancestors, Common with Potential Monodomain Crocodile and Turtle Defensins. Biology, 2022, 11 (5), ⟨10.3390/biology11050690⟩. ⟨hal-03673045⟩

Maëva Halgrain, Sonia Georgeault, Nelly Bernardet, Maxwell Hincke, Sophie Réhault-Godbert. Concomitant Morphological Modifications of the Avian Eggshell, Eggshell Membranes and the Chorioallantoic Membrane During Embryonic Development. Frontiers in Physiology, 2022, 13, ⟨10.3389/fphys.2022.838013⟩. ⟨hal-03666492⟩

Mégane Brégeon, Daniel Tomas, Benoît Bernay, Céline Zatylny-Gaudin, Sonia Georgeault, et al.. Multifaceted roles of the egg perivitelline layer in avian reproduction: Functional insights from the proteomes of chicken egg inner and outer sublayers. Journal of Proteomics, 2022, 258, pp.104489. ⟨10.1016/j.jprot.2022.104489⟩. ⟨hal-03541518⟩

Thierry Moreau, Joël Gautron, Maxwell T. Hincke, Philippe Monget, Sophie Réhault-Godbert, et al.. Antimicrobial proteins and peptides in avian eggshell: Structural diversity and potential roles in biomineralization. Frontiers in Immunology, 2022, 13, pp.1-29. ⟨10.3389/fimmu.2022.946428⟩. ⟨hal-03752173⟩

Joël Gautron, Clara Dombre, Francoise Nau, Cyril Feidt, Laurent Guillier. Review: Production factors affecting the quality of chicken table eggs and egg products in Europe. Animal, 2022, 16 (Suppl. 1), pp.100425. ⟨10.1016/j.animal.2021.100425⟩. ⟨hal-03508011⟩

Joël Gautron, L. Stapane, N. Le Roy, Y. Nys, A. B Rodriguez-Navarro, et al.. Avian eggshell biomineralization: an update on its structure, mineralogy and protein tool kit. BMC Molecular and Cell Biology, 2021, 22 (1), ⟨10.1186/s12860-021-00350-0⟩. ⟨hal-03256042⟩